The present invention relates to a method for sensing the readiness to steer or the driving behavior of a driver, and a method for generating adaptive warning times.
The invention relates in particular to a method for sensing the readiness to steer or the steering behavior of the driver of a motor vehicle, at least one pressure and/or contact sensor which supplies an electrical signal when it is touched and/or pressure is exerted being integrated into the steering wheel of the vehicle or mounted on the steering wheel.
A device is described in DE 198 02 249 C2 to regulate the travel speed of a vehicle. The sensing of the readiness to steer is, however, not sensed.
In known driver assistance systems, for example cruise controller with distance control, cornering warning systems or automatic lane detection or lane guidance systems there are often critical situations in which the driver is warned or must very quickly assume control of the vehicle himself again.
This is usually carried out in the known systems by an audible warning signal. The prewarning time or the warning intensity is usually a constant variable and is not adapted to the degree of attentiveness or readiness of the driver to act. This has the disadvantage that in many situations the warning comes too late or in many situations too early, which the driver experiences as an attempt to relieve him of control.
An object of the invention is to provide a method which can be used to determine the readiness to steer or the steering behavior of the driver. Furthermore, the driver is to be warned of imminent dangers as a function of her readiness to steer. The intention is thus to be able to increase the attentiveness of the driver as a function of the situation.
This object has been achieved according to the invention by the pressure sensor and/or contact sensor has a multiplicity of sensor elements or sensor segments arranged along the circumference of the steering wheel. Each of the sensor elements or sensor segments has, in the cross-section of the steering wheel rim, a multiplicity of pressure-sensitive and/or contact-sensitive zones so that it is possible to detect whether the driver""s hand grasps the steering wheel from the inside, outside, top or bottom.
The readiness of the driver to steer can easily be determined with this simple but effective measure.
The position and the pressure of the hands at a particular time can be evaluated, and a signal or coefficient which represents the readiness of the driver at a particular time to execute a necessary steering movement can be evaluated.
According to one particularly advantageous currently contemplated embodiment, this signal or coefficient can be used in an evaluation unit to generate, for example, an audible, optical, haptic or similar warning to the driver as a function of the travel situation at a particular time or the events on the road detected around the vehicle.
The timing of the generation of the warning can be dependent on the readiness of the driver at a particular time to execute a necessary steering movement.
Alternatively, or additionally, the warning can be generated as a function of the driver type which is derived as a further signal variable or coefficient by a relatively long measurement and chronological statistical evaluation or formation of mean values.
The pressure with which the driver grasps the steering wheel can be determined by the pressure and/or contact sensor, as a result of which a pressure signal is generated by the evaluation unit.
Finally, there is provision for the pressure signal to be used to actuate vehicle-mounted vehicle-occupant protection and/or driver assistance systems which prevent or reduce an accident. Such systems are equipped with sensors for sensing the surroundings, for example cameras, radar, etc., and/or actuators for influencing the lateral movement and/or longitudinal movement for a steering or braking intervention.